In a single clinical study that enrolled 96 patients with advanced or spreading BCC, Erivedge shrank the tumors in 30% of those with metastatic cancer and shrank or eliminated tumors in 43% of patients with locally advanced cancer.

That was enough for the FDA to approve Erivedge under its speediest form of review.

The approval comes with the FDA's "black box" warning -- it's most severe safety alert -- noting that the drug carries a risk of causing stillbirth or severe birth defects. It cannot be used by pregnant women. Men taking Erivedge must use condoms, even if they have had vasectomies, to avoid unintentionally contaminating their female partners with the drug.

Erivedge will be available in the U.S. within two weeks. However, it will not be sold at retail pharmacies, but must be dispensed at "specialty pharmacies" where staff is trained to offer patient education.

Erivedge is made by Genentech, a Roche company. The firm says it soon will seek approval in the European Union.